The present invention relates to a disc cartridge having a disc-shaped recording medium, such as an optical disc held therein.
Up to now, a disc cartridge, having a disc-shaped recording medium, such as an optical disc, rotatably housed therein, and which is loaded on a disc recording and/or reproducing apparatus, is housed therein as a disc-shaped recording medium, has been in use extensively. This sort of the disc cartridge, comprising a disc-shaped recording medium, housed in a main cartridge body unit, can be loaded/unloaded for the disc recording and/or reproducing apparatus, with the disc-shaped recording medium in a protected state.
As this sort of the disc cartridge, such a one comprising a disc-shaped recording medium, housed for rotation in a rectangular-shaped main cartridge body unit, is in widespread use.
Meanwhile, among the commercially available disc-shaped recording mediums, housed in disc cartridges, there are those common in size but different in the recording and/or reproducing system. The disc-shaped recording mediums, different in the recording and/or reproducing system may not be recorded and/or reproduced on a common recording and/or reproducing apparatus with compatibility. The disc cartridge, housing a disc-shaped recording medium, substantially common in size, also has a outer substantially common outer shape. That is, a disc cartridge substantially common in outer shape but different in the recording and/or reproducing system is now presented to the market. Among these commercially available disc cartridges, there are those having discriminating parts for discriminating the sort of the disc-shaped recording mediums housed therein. These discriminating parts are mechanically or electrically discernible, using a cartridge discriminating unit provided to the recording and/or reproducing apparatus carrying the disc cartridge, but are difficult to discern readily on visual observation.
Thus, such a disc cartridge, in which the sort of the disc-shaped recording medium, housed therein, may readily be discerned based on the outer shape of a main cartridge body unit, has been proposed. An example of this disc cartridge is disclosed in the Japanese laid-Open Patent Publication H11-353845 (Patent Publication 1).
In the disc cartridge, disclosed in the Patent Publication 1, the inserting end into the recording and/or reproducing apparatus has a substantially arcuate lateral side as an inserting end to the recording and/or reproducing apparatus, so that the inserting direction into the recording and/or reproducing apparatus may readily be identified, while the mistaken insertion into the recording and/or reproducing apparatus may readily be prevented from occurring. In addition, since the lateral side is arcuate-shaped, the disc cartridge may be smaller in size than a rectangular-shaped disc cartridge.
In the disc cartridge, described in this Patent Publication 1, the lateral side of the main cartridge body unit is arcuately-shaped. However, the disc cartridge is not reduced in size in keeping with the disc-shaped recording medium housed therein.
Moreover, the rectangular-shaped disc cartridge, so far used extensively, may be inserted into or detached from a cartridge supporting part of a cartridge holder provided to the recording and/or reproducing apparatus. That is, the rectangular-shaped disc cartridge may be loaded or unloaded in stability by causing its movement along an inserting guide part provided to the recording and/or reproducing apparatus.
If, with the rectangular-shaped disc cartridge, an engagement recess, engaged by a mating engagement portion of the ejection unit provided to the recording and/or reproducing apparatus, is provided, it is naturally provided in a flat surface parallel to the inserting direction.
If the inserting end of a disc cartridge into the recording and/or reproducing apparatus is arcuately-shaped, as in the disc cartridge shown in the Patent publication 1, for reducing the size of the disc cartridge in keeping with the disc-shaped recording medium accommodated therein, it may be difficult to provide the engagement recess, engaged by a mating engagement portion of the ejection unit provided to the recording and/or reproducing apparatus, in a flat surface extending parallel to the inserting direction. That is, the engagement recess, which enables an ejection unit to be operated in stability during the operation of inserting the disc cartridge into the recording and/or reproducing apparatus, it may become impossible to provide the recess in the flat surface extending parallel to the inserting direction, as a result of the attempt to reduce the size of the disc cartridge.
In a disc cartridge in which, for further reducing its size, an area approximately one-half of the inserting end into the recording and/or reproducing apparatus, it becomes impossible to provide the engagement recess, engaged by the mating engagement portion of the ejection unit, in the flat lateral surface extending parallel to the inserting direction.